Motor-driven chain saws of this kind typically have two handles, namely, a holding and operating handle provided on the back end of the housing and a holding and guiding handle located farther forward. While the holding and operating handle on the back of the housing is approximately coaxial with the guide bar, the front holding and guiding handle is disposed in a transverse plane, usually a centroidal plane, between the guide bar and the holding and operating handle. With this arrangement of the handles, the tool can be held and guided securely by the operator with both hands while the tool is in operation.
In a known tool of this kind, the motor-driven chain saw Type 034 manufactured by Andreas Stihl, the holding and guiding handle surrounds the machine housing on both longitudinal sides and on the top in a spaced apart manner; both ends of the handle are secured to the underside of the housing and are joined by a damping or shock absorbing member. To increase stability, a strut is provided on the top of the holding and guiding handle. This strut extends rearwardly and downwardly and along one longitudinal side of the housing, and is secured there at its end. The holding and guiding handle, which is freely accessible at three sides, that is, the two longitudinal sides and the top, is intended to permit the tool to be guided securely even in emergencies.
A disadvantage of the known handle arrangement is that the protective cover on the longitudinal side of the housing near the guide bar, which covers the portion of the guide bar, saw chain and drive pinion near the housing, must be extended downwardly to near the bottom of the tool for safety reasons; otherwise, the operator's hand, gripping the holding and guiding handle in this area, could be injured by the moving saw chain. Extending the cover so far downwardly, however, makes it considerably more difficult to eject chips, and under adverse conditions the chip ejection channel may become plugged, which causes undesirable, time-consuming interruptions in the work.
A further disadvantage of the known handle arrangement is that because the holding and guiding handle is extended around the tool, both ends of the handle are secured to the underside of the machine in overlapping fashion, separated by a damping member, because as a result either the tool housing must be extended very far downward, or else there will be a sill or ledge on the bottom of the tool, which hinders sliding the machine on its bottom. The handle is secured such that it protrudes beyond the base wall so that the securing location must also be disposed as close as possible to the front to prevent the tool from tipping forward if it is set down on the ground. Securing the holding and guiding handle in this way does not correspond to an arrangement of the handle in a centroidal plane of the tool, an arrangement which is highly advantageous for tool operation.